Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M3LU-R4 B UL found under Transmitter Temperature Electric by M Systems. The National Stock Number assigned to this part is 6685016153111, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like M3LU-R4 B UL.